[Integrated control of main diseases and insects of Dendranthema morifolium]

The main virus diseases, downy mildew, leaf spot, leaf-injuring insects and aphid's natural enemies in Dendranthema morifolicum were investigated and identified, and the development laws of pests and natural enemies were studied respectively. The effectiveness of integrated control of stem-tip culture, film covering, interplating with tall stalk crops, micronutrient application, terminal bud excising, and use of natural enemies were evaluated. The results showed that after the application of above integrated control measures, the virus-free rate and the yield-increasing rate of the seedlings from stem-tip culture were about 60% and over 50%, respectively. The incidence of downy mildew and leaf-spot decreased by 28% to 30%. The injurious insect density reduced by 40%. The detection of pesticides residue indicated that three pyrethroids insecticides such as cypermethrin, fenvalterate, and deltamthrin were applied one month before harvest, the residues in Dendranthema morifolium after harvest were 0.017, 0.058 and 0.019 mol.L-1, respectively, and all lower than the relevant tolerance values.